Assessment of Antibacterial Activity and the Effect of Copper and Iron Zerovalent Nanoparticles on Gene Expression DnaK in Pseudomonas aeruginosa

Abstract

The use of antibiotics in addition to drug resistance can cause harmful side effects. The presence of nanoparticles as novel antibacterial agents and carriers for drug delivery are important for the treatment of diseases. Pseudomonas aeruginosa is an opportunistic pathogen and resistance to antibiotics that infects damaged tissues and also people with a weak immune system. In this study, zerovalent copper (Cu0) and iron (Fe0) nanoparticles with the average size of 25 nm and less than 50 nm, respectively, were synthesized by chemical reduction method. Scanning electron microscopy (SEM) has been used to determine the particle size and morphology. The antibacterial effect of these nanoparticles against Pseudomonas aeruginosa was assessed. The minimum inhibitory concentrations (MIC), as well as minimum bactericidal concentration (MBC), were determined using colony count and measurement of optical density methods. The results of treatment Pseudomonas aeruginosa with zerovalent iron and copper nanoparticles showed that the rate of growth was reduced in a dose-dependent manner and these nanoparticles showed that bactericidal effect on Pseudomonas aeruginosa. The effect of zerovalent iron and copper nanoparticles on heat shock gene expression dnaK were studied using real-time RT-PCR. Gene expression levels indicated that dnaK expression was reduced 10- and 7-fold in treatment with Fe0 and Cu0, respectively. Since the nanoparticles inhibited the bacterial growth, the expression level has decreased compared with control.